Summary The Training Program in Host-Pathogen Interactions (HPI) has been supported to train predoctoral students in the areas of microbial pathogenesis and host defense for the past 4 years. This revised renewal application seeks to build upon the many strengths that have been developed at UMCP over the initial support period and to expand our program in host-pathogen interactions. Our 23 training faculty are remarkably interactive, allowing our trainees to be exposed to a variety of diverse research techniques. Multi-disciplinary approaches to pathogen research will be emphasized to take advantage of our widespread expertise in diverse research areas including biomaterials and nanosciences, computational biology and genomics, microbiology and immunology, and microbial pathogenesis. Trainees in the HPI program will be exposed to a variety of career alternatives, and attend seminars from previous trainees who have gone on to pursue careers in clinical trials administration, scientific review, biodefense, intellectual property, science writing, and entrepreneurship. A new internship with MedImmune provides opportunity to explore Biopharma first-hand. The didactic component of this training program is organized by the Biological Sciences Training Program (BISI) and the research program is guided by a highly qualified team including the Training Program Co-Directors, an Internal Steering Committee, and an External Advisory Board comprised of internationally recognized experts in bacterial pathogenesis and host defense. Predoctoral students are selected for this program from a large and increasingly qualified applicant pool. Of the 14 trainees supported by the HPI Training Program two (2) are underrepresented minorities (15%), and 10/14 trainees were women. Of the 23 faculty trainers, 1 is an underrepresented minority and 5 are women (22%). This training program takes advantage of the close proximity of UMCP to the NIH, FDA, USAMRIID, and the Department of Homeland Security and we have sent students into laboratories from all of these institutions to learn techniques. Finally, our trainees present their research at local, national, and international meetings. Thus, the Training Program in Host-Pathogen Interactions plays a key role in the continued development of this discipline at the University of Maryland, College Park.